Simplified Design for Structural Walls - Simplified Design of Reinforced Concrete Buildings - page 204

From wind load analysis (see Chapter 2, Section 2.2.2.1):

E-W direction

M u = 1.6 [(6.9 63) + (13.4 51) + (12.9 39) + (12.2 27) + (12.6 15)]/2

= 1712 ft-kips/shearwall

N-S direction:

M u = 1.6 [(16.2 63) + (31.6 51) + (30.6 39) + (29.2 27) + (30.7 15)]/2

= 4060 ft-kips/shearwall

(c) Values of P u and M u for the 2nd and 3rd floor levels are obtained in a similar manner:

For 2nd floor level: 2-8 ft segments: P u = 171 kips

1-20 ft-8 in. segment: P u = 218 kips

E-W direction: M u = 1016 ft-kips/shearwall
N-S direction: M u = 2400 ft-kips/shearwall

For 3rd floor level: 2-8 ft segment: P u = 128 kips

1-20 ft-8 in. segment: P u = 162 kips

E-W direction: M u = 580 ft-kips/shearwall
N-S direction: M u = 1367 ft-kips/shearwall

(2) Design for Flexure in E-W direction

Initially check moment strength based on the required vertical shear reinforcement No. 4 @ 10 in.
(see Example 6.4.2).

(a) For 2-8 ft wall segments at first floor level:

A st = 3.84 in. 2

P u = 219 kips

M u = 1712 ft-kips

w = 96"

˜ w = 96 in.

For No. 4 @ 10 in. (2 wall segments):

A st = 2 × 0.24 × 8 = 3.84in. 2

⎛
⎜

⎞
⎟

f y
ʹ

A st
w h

3.84
96

60
4 =

⎛
⎜

⎞
⎟

ω=

f c =

0.038

× 16

P u
w h

219

α=

f c = 4 =

0.036

ʹ 96 × 16 ×